


Kittens

by Vathara



Category: Asobi ni Iku yo!
Genre: Gen, How to make crack less cracky, Worldbuilding
Language: English
Status: Completed
Published: 2014-06-05
Updated: 2014-06-05
Packaged: 2018-02-03 13:14:28
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,991
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1745939
Author URL: https://archiveofourown.org/users/Vathara/pseuds/Vathara
Summary: <blockquote class="userstuff">
              <p>Catians and humans are just similar enough to make the differences dangerous. A bit of SF worldbuilding.</p>
            </blockquote>





	Kittens

**Author's Note:**

> Spawned by bunnies on “how would Asobi ni Iku yo! SF crack be... well, less cracky, more SF?” Not my usual fandom, but the potential for SF worldbuilding was too much fun to pass up. Cat Planet Cuties, definitely not mine. Set in a bit of eps. 4, 5 and 6.

The problem with saying you had to go clean your room, Kio reflected, was that you had to make a stab at actually cleaning your room.

Not that it was really that dirty, he did clean regularly. Mostly. Uncle Yuichi’s jokes about his bachelor pad whenever the piles got out of hand saw to that. But still... cleaning.

Kio heaved a sigh, and nudged his glasses up. He’d said he would, so it was time to get to it.

_Besides, I really do have a reason. If Eris is reading... stuff under my bed... um. I should find somewhere else to put it. Before she gets any more wrong ideas_.

And she wasn’t the only one. The whole Catian negotiating team, in _school swimsuits_....

It didn’t help that he could almost hear Uncle Yuichi’s snicker of, _“I bet they won_ that _negotiation, hands down.”_

Kio thumped his head on his knuckles, trying to drive that image out. Somehow, offering Eris a place to stay had morphed into having his home turn into an alien embassy where Earth laws no longer applied. It was _weird_. Weirder, in a way, than watching Assist-a-roids pop out of the ground where Eris had seeded nanomachines in his backyard. This was the Kakazu house, but the Catians didn’t act at all like his family would have expected people to behave-

“May I come in?”

Kio froze. The manga in his hand could only be called _family_ in the way Uncle Yuichi called beer a friendly drink. He stuffed it behind a stack of film club videos and hoped for the best. “Dr. Durel! If - if this is about Eris....”

“Hmm, not really.” The dark-haired doctor stepped lightly in, quiet and relaxed. “Though I’m glad you kept your head with that silver vine powder. Now that I’ve got a sample I should be able to create some antidote sprays for all of us to carry. It’s probably not more than a mild stimulant to a Catian who’s not in heat, but better safe than sorry.”

Kio let out a quiet breath of relief, tempted to collapse into a chair right there. He’d been fighting off nightmare images of some idiot tossing an industrial-sized box of cat powder over the wall, and every last one of the Catians going berserk. He’d seen what Eris had done with that hammer. Shredded drapes would be the least of his worries.

Though he was even more worried that physical destruction would be the last thing on their minds. Eris was being way too up front about what she wanted, and Chief Chaika had called him a naughty boy with a grin that was downright scary, and... well... eep.

“Actually,” Dr. Durel’s sucker clicked against her teeth as she worked it around, “I came for your medical checkup.”

...And the world had just gotten weird again. “Mine?” Kio tried not to squeak.

“You are part of the embassy.” Dr. Durel held up a small, sleek black and white device, a little larger and more complicated than Eris’. “Relax and sit down. Mostly I just need to confirm Eris’ preliminary scan when she treated your headache. It’ll only take a few minutes.”

“Oh.” Kio swallowed, and sat down on his bed. “Okay.”

“Great!” Dr. Durel snagged his desk chair and sat down a few feet away, tail twitching with interest. “Would you mind if I took a DNA sample as well? We’re all curious about how close your species really is to ours.” She held out a hand, gloved palm up.

“I’m kind of curious about that too,” Kio admitted, resting his hand on hers long enough for the doctor to touch her scanner to the back of his wrist. There wasn’t even a pinch. Just a little tingle, like one snowflake melting on his skin. “You look so much like us. Our scientists had pretty much decided years ago there was no way that could really happen. I mean, just the odds of all the proteins and sugars being the right handedness, so Eris can eat Earth food and not starve-” He blushed. He kind of had to. “Sorry. You’re space travelers. There’s no way you don’t know that already.”

“Wrong-chirality worlds are actually a distinct minority in our galaxy.” Dr. Durel raised her scanner above his head level, moved it slowly down to finally angle the sensors at his feet. “A good atmospheric sample will tell you which kind of ecosystem you’re dealing with.”

“Really?” Kio sat up, intrigued. “So you can tell a lot about a planet without ever landing. That’s a good idea. What else can you tell-”

Stupid. _Stupid_ ; he had the doctor alone, for once. He could geek out later.

“Look....” Kio scratched at the back of his head. “Can I talk to you about Eris?”

Dark ears perked up. “That’s very considerate of you, Kio. Partners should know something about each other for a positive sexual encounter. Eris has had the opportunity to sample your planet’s sensual literature, but you haven’t had a chance to read any of ours. I’ll arrange for some translations.”

Alien sensual literature. All of geekdom was going to hate him. “I’m too young for this!”

The Catian blinked at him.

“Your first time... it should be... special,” Kio got out. “With someone you care about. Eris - she’s wonderful. But we haven’t known each other long. I don’t want her to make a mistake.” He took a breath, one hand splaying over the covers, trying to sketch out the right words. “Maybe this is an embassy under Catian laws. But this isn’t about the law! Eris should have someone she knows cares about her. Not just someone who - who only thinks she’s available....” Oh man, how could he explain if that didn’t work?

Dr. Durel was giving him a very curious look. Reached up, and tapped her glasses as if coming to a conclusion. “Hmm. So there are sociocultural considerations, as well as biological ones. Interesting.” Her scanner beeped. “Ah. Would you like to see?”

“Ah... okay?” Oh boy, he hoped that meant the doctor realized there was something wrong with the whole situation - oh, _wow_.

Durel’s scanner did holograms, too. Kio recognized two sets of chromosomes, stylized not that much differently than they’d show up in a biology textbook; mostly blue, but highlighted here and there with bits of purple and red on one, and purple and yellow on the other. “That’s two people’s DNA, right?”

“Correct,” Dr. Durel nodded, tapping the image on her left marked up with purple and yellow. “This is yours.” She gestured at the other. “This is a Catian. Purple are the analog genes; they serve pretty much the same purpose, but they’re not quite the same. Red are genes Catians have and humans don’t, while yellow are human genes we don’t have.” She shrugged. “There are more differences in the proteosomes, but those are trickier to interpret. This is a good place to start looking at how close our species are.”

How close. But that meant - she couldn’t be implying- “All that blue is where we’re the same?” Kio blurted out. “That’s not possible!”

“It certainly seems improbable,” the doctor stated, eyeing her data. “I’m going to want to look at a lot more human samples. But I have to say I’m not that surprised. Eris wouldn’t be so interested if you didn’t have the right scent where it counted.”

Okay, he was kind of getting used to the way everything female in his life seemed to want to stomp on his ego, but that was new. He smelled? Maybe he needed to take a bath more often.

“What’s interesting is some of the differences. This one, for example.” Dr. Durel tapped one red band, expanding and highlighting it with a paragraph of alien text that hovered there a moment, then shimmered into Japanese. “This codes for the neural connections used in purring. It’s critical for healthy space travel in our race, especially if you expect to encounter periods of free fall.”

His traitor brain was putting together Eris and purring. Kio tried not to blush. “Wait. You need to purr for zero gravity? Seriously? Why?”

“Bone regeneration,” the doctor said succinctly. “Free fall’s very bad for bone demineralization.”

“Oh. Yeah.” Kio nodded. “I read something about that... wait, what does purring have to do with it?”

“It hits the right frequencies to stimulate bone growth. We could handle it medically, but why put it all on the doctor when you can clear some of it up yourself?” Dr. Durel minimized that gene, poked a few others. “So, do you want that one?”

_“What?”_ He couldn’t have heard that right. No way.

“Kio.” The doctor rested her scanner in her lap, folding her hands together to give him a thoughtful look. “You’re part of the provisional Catian embassy, and if all goes well you’ll be part of the permanent one. All three of you will be going into space, sooner or later. Bone strength is essential to your health. We have treatments for weakened bones in Catians, but it will take some time to be sure they’re as good for humans. There’s no need to risk your health in the meantime.”

Space. Dr. Durel thought he was going to get into _space_.

_Why me? I’m nobody special. They don’t take film geeks as astronauts_.

No, they took tough, smart people who didn’t freak out under pressure. Like, say, someone shooting at them. They took people like Manami, and Aoi. Eris with her smiles and her self-confident agility made a much better astronaut than he ever would. Even if she hadn’t already been a space alien.

_Alien. Focus!_ “You - you’re talking about genetic engineering?” Kio blurted out. “Me?”

“It’s a valid medical technique among both our species,” the doctor nodded. “Your genetic surgery is still at a rudimentary level, given you don’t have nanomachines yet, but humans are already splicing out faulty DNA for more effective versions. This would just be a more advanced technique, with the nanomachines doing a little delicate work to establish the circuit as if it’d grown in from conception. No trouble at all, really.”

“No trouble - can I think about this?” Kio stammered. “It may not be a big thing to you, but to me it’s.... different.”

“All right,” Dr. Durel inclined her head, bringing up a few of the other red-marked genes she’d been poking. “But I’m going to insist on these.”

Kio nudged his own glasses for a better focus. “Immune system adjuncts?”

“They’ll let your body recognize a few things Earthling ecosystems never dreamed up,” the Catian said briskly. “We’ve screened and decontaminated everyone on our mothership, but, well - Catian, human, or otherwise, sapients are sapients. We’re not expecting any other species to drop by while we’re here, but,” she winked at him, “you weren’t expecting us, either.”

_That’s for sure_ , Kio thought, dazed. “And since we’re the embassy, if someone does show up, they should come here first? Which means - you want a firewall. If we can’t catch an alien disease, then we can’t spread it to the rest of the neighborhood. Everybody else stays safer.” Assuming his neighbors intended to stick around at all. Gunfire in the middle of the night kind of made people nervous.

_So why am I still here?_

Well... Eris. And Aoi and Manami. And everyone else in the crew he’d met so far. He liked Eris’ people. Even if they did make him blush. Uncle Yuichi liked them, enough to help him break into a military base to get Eris back, and Uncle might be friendly with everyone but he didn’t really _like_ that many people.

Uncle had helped him break in, and given him a gun loaded with tranks to do it with. Kio still wasn’t sure how he felt about that. He hadn’t had to use it, thank goodness - but Uncle Yuichi didn’t give you things that just _looked_ like they could be used.

_I should... I should learn to shoot. More than just the basics Uncle showed me. I don’t_ want _to, but if Eris gets taken again - I need to be able to help_.

“Okay,” Kio breathed. “What do we need to do to set up the immune system stuff?”

“Oh, that’s a simple program. I’ve prepped it already.” Dr. Durel picked up her scanner. “Just give me your hand.”

The tingle this time was cooler, and longer.

“That should do it,” the doctor said briskly. “Get some rest and fluids for the next few days. You might be a little tired and achy. Outside of that, we’re set.”

_That’s it_ , Kio reflected, looking at the back of his hand. _Right now, there are nanomachines in there, fixing my immune system to be... just a little alien. And it looks like nothing’s happening. Ms. Itokazu would have a fit_.

Would she ever. The leader of Japan’s Beautiful Contact sect would probably be yanking her hair and sobbing, declaring that advanced genetic engineering _done by aliens_ should at least have the dignity to turn his veins glowing green. Or something.

Kio flexed his fingers, wondering if he should start filming some of what the Catians did every day. Especially the stuff that didn’t look “realistic”. Who’d believe it if he didn’t?

_Speaking of reality_. “Are you going to be treating Aoi and Manami next?”

“Hmm.” Studying her results, Dr. Durel waved a thoughtful hand. “Manami first. She’ll be simpler. I’m going to want some time to analyze Aoi’s DNA and brain scan thoroughly. Psychic abilities can be delicate, and I want to review the available science for the latest recommendations.”

Kio had to do a double-take. “ _Psychic_ abilities?”

“She’s an apporter,” the doctor nodded. “Object translocation. We caught a few glimpses on Eris’ recordings. I wonder what her range is? Such abilities aren’t all that common among Catians, but they do exist. Given how close we are genetically, I suppose I’d be more surprised if you didn’t have them.”

_Aoi’s a psychic_. Kio had to lean back a bit, shaken. _Wow. What else don’t I know about my friends?_ “Why didn’t she tell me?”

Almost at his doorway, Dr. Durel paused. “Is it something you don’t talk about in your culture?”

“No - well - I guess most people don’t even think it’s real,” Kio admitted. “Like aliens.”

The doctor’s tail twitched, sucker-stick swiveling as she smiled. “We’re real.”

“I know,” Kio nodded. “But I wonder how many people still don’t believe that.” He drew his fingers through his hair, thinking. “You know, I bet the real reason she didn’t say anything was that it was part of her cover. Being normal. Pretending she wasn’t a secret agent. But she and Manami are here now. They shouldn’t have to pretend they’re something they’re not. They’re great the way they are. They’re _amazing_.”

Dr. Durel touched her glasses. “Maybe you should tell them that.”

Kio gulped. “Oh. Um, I-”

“Just think about it.” Smiling, the doctor headed out to track down Manami. Who might be trying to blow something up. Again.

_And she missed the manga. Whew_. Kio sighed in relief. He had a bad feeling quiet time alone in his room might be a little harder to come by in the future.

He would have to think about it, though. For one thing, if he just told the girls how amazing they were, they’d never believe him. When they shot intruders and crashed cars and ran off stark naked down the street to rescue a kidnapped Assist-a-roid, they were just being themselves. Like he was with a videocamera. How were they supposed to believe that was awesome?

_So I can’t tell them. I’ve got to_ show _them. Somehow_.

Which would be hard to do as long as he didn’t really know what they did. They were secret agents, one of whom was psychic, both of whom knew how to use guns and blow stuff up. But that couldn’t be everything about being a secret agent. Heck, it probably couldn’t be most of it.

_I need to know more. I need to... ask questions_.

And Eris was asking lots of questions. Huh.

_We’re supposed to help her learn about Earth, right?_ Kio grinned. _I think I have a plan_.

* * *

One kidnap attempt and a set of weird power armor later, Kio had even more questions. Which was even trickier, because Aoi did not want to talk about her definitely not-Catian advanced power armor. Or why it’d shut down on her. Or who - or _what_ \- she’d been fighting. Seriously did not want to, to the point of apporting a towel into her hands to gag Manami when the redhead demanded an answer.

Then Aoi realized he was still watching. And froze.

But he’d had time to think about it, and Kio was pretty sure he’d figured out exactly what he wanted to say. “Awesome! Can you do that again?”

Manami blinked. Aoi blushed. And Eris smiled, like a patch of sunlight.

_Yeah. This is going to work_.

* * *

“Oh, that was so close.” Captain Kuune hugged herself as Eris trudged woefully back to her quarters for a post-heat-medication rest before she headed back to Earth. “If humans weren’t compatible enough to use Catian power armor, I don’t like to think about what we might have had to do to rescue her. I’d hate to set back all our negotiations for the embassy, but when one of the crew’s in trouble....”

Studying her latest scans, Dr. Durel raised an intrigued brow. _That’s interesting_. “Closer than you know. Most human males we’ve scanned so far wouldn’t be compatible with the security protocols, even with a little helpful tinkering.”

That got the captain’s full attention. “But Kio is? That’s wonderful! I know Eris wants him as a partner.”

“Then you might want to slip her some hints to slow down a little,” Durel advised. “I know it’s hard to believe about our sweet little investigator, but she’s scaring him. And I think I finally know why.” She licked her sucker; cherry, these humans had wonderful flavors. “You’re not going to like it.”

“Like it or not, I’d better hear it,” Kuune sighed. “It’d be awful if we couldn’t successfully interact with a species so close to our own. How bad is it?”

“Well....” Durel drew out the word, putting a few last thoughts in order. “That’s part of the problem. They look like Catians. But in some small, important ways, they’re not like us. You know Kio’s sixteen?”

“Yes,” Kuune nodded. “As old as Eris-”

“Nope.”

The captain’s ears lowered. “No?”

“He’s sixteen _years_ old. Earth-local. Terran,” Durel stated. And that had been a nasty shock. “I’ll have to check with Astrogation to give you accurate conversions, but one of our cycles is at least two of their years long.”

The color drained from Kuune’s face. “ _Two_ of their years? But, that means....” She covered her face with her hands. “Oh, this is worse than the swimsuits! We’ve been harassing a _kitten?_ ”

“Physiologically, he’s no kitten,” Durel said practically. “Humans haven’t optimized their systems for longevity yet, much less invented housekeeping nanomachines.” Both of which were easily solved problems, thankfully. She liked their little embassy. “But when it comes to life experience - he’s a little younger than Melwin. So yes, Captain. Eris _did_ scare him.”

Kuune shook her head, unwilling to lower her hands. “He must think we’re awful.”

Durel patted her on the shoulder. “Not at all. Kio’s a very level-headed youngster. He knows we’re strangers here. And trust me; from my scans, Eris _definitely_ hasn’t scared him off.” She chuckled. “I got to hear an awkward speech that pretty much boiled down to, Kio wants to make sure she gets a good, long courtship first. So she can make up her mind if there’s any other male she likes better.”

“Long courtship?” The captain lowered her hands, confused. “They’ve known each other for _weeks_. He took her into his house, he feeds her, he plays with her... and what other male could she be interested in?”  

“Kio doesn’t know how compatible he is, or that other males wouldn’t be,” Durel said practically. “And so far as I can tell, the usual human female to male ratio is almost one to one.”

She waited, giving that a chance to sink in. The Catian ratio was about thirty to one. Males were rare and valued; and while the admirable ones set up stable relationships with a small group of mothers of their kittens, there were plenty who just drifted between females as heat cycles hit and left. It wasn’t perfect, but that was the way life was.

_Only it’s not that way for humans_ , Durel reflected. “Can you imagine, having enough males around that they make up most of your military? A ship like ours, going out into the universe and taking risks - if the literature we’ve collected is accurate, they might not put females on it at all.” She whistled around her sucker. “Kio broke into a military base after Eris when he hasn’t had _any_ combat training. Apparently human males are supposed to protect their females, just like we’d expect anyone to protect kittens. When Eris protects _him_ \- it must be like his whole world goes into free fall. Humans may look like us, but for some things, I think they may have more in common with fauxes.”

“Oh my.” Kuune frowned, likely bringing to mind everything she knew about the hardy little endurance hunters and scavengers native to Catia’s forests. “I knew Kio was unusual when Eris told us his _uncle_ raised him, but... you think humans pair-bond?”

“More than that,” Durel sighed. “With that many guys for every girl? I’m betting they compete like fauxes, too. Males _and_ females. At least, that might explain why Kio’s so confused.”

The captain’s tail swished, a long flow of agitated purple. “This could be a problem.”

“On both sides,” Durel acknowledged. “Eris wants a good friend and sexual partner. Kio, Aoi, Manami... humans are so _serious_. We need to give them some time to think about this.” She plucked out her sucker, twirled it while she thought. “I hope Eris can stand it. She has a lot more patience than I realized, but humans are going to take a _lot_ of work.”

“It’ll be worth it,” Kuune said confidently. “I’ve looked after Eris since she was a shy little kitten. She always wanted to explore, but she wanted a family and sisters of her own, too. If things go right with those girls, she’ll have them.”

Dr. Durel arched her brows. “The girls too? Doable. I’ll program full gamete conversion sets for all of them. Aoi’s will be tricky; humans may not have officially met other species, but her genetic profile is definitely odd. Still, so long as I have a few weeks to work with, we can handle it.”

The captain did a double-take. “For all of them?”

“Eris wants kittens eventually, right? Well, humans and Catians are very, _very_ close. All four of them should discuss it, but there’s no reason they can’t have some of each.” With a glance to make sure they were unwatched, Durel pulled up her projected DNA alterations, and tapped the option for a hologram of the prospective offspring.

Kuune started; almost melted, smile as fond as Chaika’s with her little rascals. “Aww. They’re so _cute_.”

They all were, though Durel had to admit she had a preference for the ones with furry ears. Manami’s youngsters would tend toward rich swirls of tabby-red, tails banded in darker and lighter scarlet and orange. Aoi’s had a variety, but most were an elegant jet black, tipped with silver-gray. And Eris’ seemed to be half and half her red and Kio’s pure sable, without a hint of stripes.

“Still, even if we’re close,” the captain began.

“Leave it to me.” Dr. Durel winked. “First, we talk them into kids that purr.”

**Author's Note:**

> Silver vine (Actinidia polygama) has effects a lot like catnip.  
> Catian cycles being at least two Earth years long: okay, this isn’t canon, but it’s an extrapolation from canon, based on what the Catians say about “two heats every cycle”. Given Eris’ first heat was in summer, if a cycle was equivalent to a year we’d see another around December. We’d probably also see Kio finding a bunker and arming himself with trank darts.... ahem. Canon we see events in December, and a second heat isn’t even mentioned. The OVA supposedly covers a bit of the next summer, and again, Eris’ next heat doesn’t come up. So this is my rough guess. It also makes the canon plot a little less cracky; a sixteen-year-old investigator/ambassador would be silly, but one who has closer to thirty years of real-life experience makes more sense. Likewise, Melwin (canon, about 12 cycles old) being allowed to take command of the mothership makes more sense if she’s mentally a bit older.   
> So my head-canon says the Catians might well have a setup like Weber’s Honorverse, where prolong treatment stretches out all of the lifespan, and new junior officers look like they’re pre-space twelve and thirteen.   
> I have to admit, part of the impetus of this story was watching the episodes with the Captain’s bell in them and headdesking. The plotline didn’t really _need_ a gamebreaker like that. I’ve now worked out in my head two alterations to canon that would nerf the bell back down to a more reasonable power level, and fit more with an SF universe. (Insert evil laughter here....) Basically, make the bell more of a “control nanomachines to remake steel and materials into a hull” rather than “create anything.” And then just have it be Dr. Durel’s DNA modifications that do the heavy lifting to be recognized as Catian, not a bell-created Emergency Transformation.


End file.
